Septic distribution box replacement costs between $500 and $1,500, with your box material and outlet size determining your final total. The main cost drivers are the box itself, trenching or backfill, replacement or rerouting of laterals, and any required permits or. Homeowners typically pay for replacing a septic distribution box based on site access, material type, and labor. Understanding these can help homeowners budget effectively. The cost is driven by box size, material, and installation requirements, with price ranges reflecting basic plastic units up to heavier-duty or re-locatable options.